Geomechanical evolution model of bedding rock landslides in construction areas: A case study of the Maidiping landslide in Tiefeng Town, Wanzhou
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摘要:
工程建设是诱发滑坡的主要原因和风险承灾对象，其中坡脚的开挖对斜坡的稳定性产生了较大的影响。在万州区内的顺层斜坡区，泥岩、页岩等软弱夹层在自然条件与工程活动共同作用下渐进破坏，导致滑坡大范围发生，造成无法挽回的经济损失，因此需要对滑坡的破坏过程进行分析与讨论。根据调查万州铁峰乡典型顺层岩质滑坡，建立了降雨与工程活动作用下滑坡演化过程的地质力学模型。通过环剪实验获得软弱泥化层的力学参数，应用FLAC3D模拟了滑坡在人工开挖和降雨条件下滑动面的剪切变形，与刚体极限平衡法相结合分析了滑坡稳定性的变化趋势，并结合野外调查结果进行了对比验证。计算结果表明，软弱夹层经历了自然缓慢软化和人工开挖快速软化2个阶段，受剪切位移控制，属于应变软化模型，强度随剪切位移增大而不断衰减，在达到某一临界位移时强度快速衰减，进而转化为滑动面，降低了斜坡稳定性。研究区内的麦地坪滑坡大变形出现在坡脚开挖后的降雨期，与实验分析结果相符。实验和模拟结果与野外调查相匹配，验证了建设区顺层岩质滑坡地质力学模型的合理性，研究结果对于顺向坡的建设活动和防灾减灾具有指导意义。
Abstract:Objective Engineering construction is the main cause and risk-bearing object for landslides, where excavation at the foot of a slope has a great impact on the stability of a slope. In the cascading slope areas, the progressive damage of soft inclusions such as mudstone shale under the combined effect of natural conditions and engineering activities has led to the occurrence of landslides on a large scale, which cause irreparable economic losses. Therefore, the destruction process of landslides needs to be analysed and discussed.
Methods A geomechanical model of the landslide evolution process under the action of rainfall and engineering activities was established based on the investigation of a typical bedding rock landslide in Tiefeng Town, Wanzhou. The mechanical parameters of the soft muddied layer were obtained by ring shear experiments. FLAC3D was applied to simulate the shear deformation of the landslide under the conditions of manual excavation and rainfall, which was combined with the rigid body limit equilibrium method to analyse the trend of landslide stability and compare with the field survey results.
Results The results show that the weak interlayer goes through two stages of natural slow softening and artificial excavation rapid softening and belongs to the strain softening model. The strength decreases continuously with the increasing shear displacement, and the strength decreases rapidly when a critical displacement is reached. The large deformation of Maidiping landslide occurs during the rainfall period after the excavation of the foot of the slope, which is consistent with the experimental results.
Conclusion The experimental and simulated results agree with the results of field investigation, which verify the present geomechanical model of the cis-layered rock landslide. The results are of guidance for construction activities and disaster prevention and mitigation of cis-slopes.
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Key words:
- bedding rock landslide /
- weak interlayer /
- geomechanical model /
- ring shear test /
- Maidiping landslide
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图 2 研究区软弱夹层分布柱状图(a)和野外观测图(b, c, d)
b.自流井组炭质页岩; c.自流井组泥质页岩; d.珍珠冲组石英砂岩和泥岩夹层
Figure 2. Column chart (a) and field observation chart (b, c, d) of weak interlayer distribution in the study area
图 4 麦地坪滑坡航拍图(a)及剖面图(b)
Figure 4. Aerial view (a) and section view (b) of the Maidiping landslide
图 6 环剪样品制备过程
a.环刀样品制备; b.环形样品制备; c.装配剪切盒; d.完整剪切盒
Figure 6. Sample preparation process of ring shear test
图 7 不同含水率下应力-位移曲线
Figure 7. Stress-displacement curves under different moisture contents
图 8 不同含水率下剪应力拟合曲线
Figure 8. Shear stress fitting curve under different moisture contents
图 9 不同含水率下样品剪切刚度
Figure 9. Shear stiffness of samples under different moisture contents
图 11 麦地坪滑坡第一阶段软弱夹层剪切位移量模拟
Figure 11. Displacement magnitude of the weak interlayer in the Maidiping landslide at the first stage
图 12 麦地坪滑坡第二阶段软弱夹层剪切位移量模拟
Figure 12. Displacement magnitude of the weak interlayer in the Maidiping landslide at the second stage
图 13 各阶段和工况下滑坡稳定性系数
Figure 13. Stability coefficient of landslides at various stages and working conditions
表 1 软弱夹层强度参数
Table 1. Strength parameter of weak interlayer
含水率 峰值强度参数 残余强度参数 σ=100 kPa σ=250 kPa σ=500 kPa cp/kPa φp/(°) cr/kPa φr/(°) τp/kPa τr/kPa τp/kPa τr/kPa τp/kPa τr/kPa 10% 22.4 34 21.0 20 75 50 200 125 350 225 17% 22.0 29 14.9 15 75 50 160 100 325 175 24% 22.1 21 7.3 11 60 40 120 75 225 125 注: c.黏聚力；φ.内摩擦角；τ.剪切强度；σ.法向应力；p, r代表峰值阶段、残余阶段 
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表 2 数值模拟参数取值
Table 2. Values of the simulation parameters
材料名称 γ/(kN·m3) c/kPa φ/(°) K/MPa G/MPa RM/kPa cp/kPa cr/kPa φp/(°) φr/(°) 砂岩(自然) 25.9 20 6 1.8×103 1.2×103 7×103 — — — — 砂岩(降雨) 26.1 18 4 1.8×103 1.2×103 7×103 — — — — 泥岩(自然) 17.2 — — 9.2 8.6 1 22.4 21 34 20 泥岩(降雨) 17.8 — — 6.4 6.3 22.1 7.3 21 11 注：γ.重度；K.体积模量；G.剪切模量；RM.抗拉强度；其他同表 1
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[1] Huang R, Fan X. The landslide story[J]. Nature Geoscience, 2013, 6(5): 325-326. doi: 10.1038/ngeo1806 [2] Runqiu H. Large-scale landslides and their sliding mechanisms in China since the 20th Century[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(3): 433-454. [3] 李守定, 李晓, 吴疆, 等. 大型基岩顺层滑坡滑带形成演化过程与模式[J]. 岩石力学与工程学报, 2007, 26(12): 2473-2480. doi: 10.3321/j.issn:1000-6915.2007.12.012Li S D, Li X, Wu J, et al. Evolutionary processes and patterns in the formation of large bedrock cascade landslides[J]. Journal of Rock Mechanics and Engineering, 2007, 26(12): 2473-2480(in Chinese with English abstract). doi: 10.3321/j.issn:1000-6915.2007.12.012 [4] Li C, Fu Z, Wang Y, et al. Susceptibility of reservoir-induced landslides and strategies for increasing the slope stability in the Three Gorges Reservoir area: Zigui Basin as an example[J]. Engineering Geology, 2019, 261: 105279. doi: 10.1016/j.enggeo.2019.105279 [5] Ouyang C, Zhou K, Xu Q, et al. Dynamic analysis and numerical modeling of the 2015 catastrophic landslide of the construction waste landfill at Guangming, Shenzhen, China[J]. Landslides, 2017, 14(2): 705-718. doi: 10.1007/s10346-016-0764-9 [6] Cen D, Huang D, Ren F. Shear deformation and strength of the interphase between the soil-rock mixture and the benched bedrock slope surface[J]. Acta Geotechnica, 2017, 12(2): 391-413. doi: 10.1007/s11440-016-0468-2 [7] 陶连金, 沈小辉, 王开源, 等. 某大型高速公路滑坡稳定性分析及锚桩加固的模拟研究[J]. 工程地质学报, 2012, 20(2): 259-265. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201202020.htmTao L J, Shen X H, Wang K Y, et al. Simulation study on stability analysis of a large highway landslide and anchor pile reinforcement[J]. Journal of Engineering Geology, 2012, 20(2): 259-265(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201202020.htm [8] Petley D N, Bulmer M H, Murphy W. Patterns of movement in rotational and translational landslides[J]. Geology, 2002, 30(8): 719-722. doi: 10.1130/0091-7613(2002)030<0719:POMIRA>2.0.CO;2 [9] 龙建辉, 赵邦强, 李坤. 顺层岩质边坡多级滑动模式及成因机理分析[J]. 中国矿业大学学报, 2016, 45(6): 1156-1163. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201606011.htmLong J H, Zhao B Q, Li K. Analysis of multi-stage sliding patterns and causal mechanisms of cascading rocky slopes[J]. Journal of China University of Mining and Technology, 2016, 45(6): 1156-1163(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201606011.htm [10] 张涛, 谢忠胜, 石胜伟, 等. 川东红层缓倾岩质滑坡的演化过程及其识别标志探讨[J]. 工程地质学报, 2017, 25(2): 496-503. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201702029.htmZhang T, Xie Z H, Shi S W, et al. Evolutionary process of red-layered gently dipping rocky landslides in east Sichuan and its identification markers[J]. Journal of Engineering Geology, 2017, 25(2): 496-503(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201702029.htm [11] 简文星, 童龙云. 川东天台乡滑坡滑带特征及其工程意义[J]. 工程地质学报, 2012, 20(5): 774-780. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201205018.htmJian W X, Tong L Y. Characteristics of landslide zones and their engineering significance in Tiantai Township, East Sichuan[J]. Journal of Engineering Geology, 2012, 20(5): 774-780(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ201205018.htm [12] Jian W X, Yin K L, Yan T J, et al. Characteristics and formation mechanism of Minguochang landslide in Wanzhou District, Chongqing[J]. China J. Geol. Hazard Control, 2005, 16(4): 20-23. [13] 李江, 许强, 胡泽铭, 等. 川东红层原状滑带土饱水软化试验研究[J]. 岩石力学与工程学报, 2015, 34(2): 4333-4342. doi: 10.13722/j.cnki.jrme.2014.1003Li J, Xu Q, Hu Z M, et al. Experimental study on water-saturated softening of red-bedded in situ slip zone soils in eastern Sichuan[J]. Journal of Rock Mechanics and Engineering, 2015, 34(2): 4333-4342(in Chinese with English abstract). doi: 10.13722/j.cnki.jrme.2014.1003 [14] 周翠英, 朱凤贤, 张磊. 软岩饱水试验与软化临界现象研究[J]. 岩土力学, 2010, 31(6): 1709-1715. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201006006.htmZhou C Y, Zhu F X, Zhang L. Study on softening critical phenomena in soft rock saturation tests[J]. Rock and Soil Mechanics, 2010, 31(6): 1709-1715(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201006006.htm [15] 王运生, 吴俊峰, 魏鹏, 等. 四川盆地红层水岩作用岩石弱化时效性研究[J]. 岩石力学与工程学报, 2009, 28(增刊1): 3102-3108. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S1078.htmWang Y S, Wu J F, Wei P, et al. Timing of rock weakening by water-rock action in the Sichuan Basin[J]. Journal of Rock Mechanics and Engineering, 2009, 28(S1): 3102-3108(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S1078.htm [16] Zhou J W, Jiao M Y, Xing H G, et al. A reliability analysis method for rock slope controlled by weak structural surface[J]. Geosciences Journal, 2017, 21(3): 453-467. doi: 10.1007/s12303-016-0058-1 [17] 简文星, 潘永亮, 李林均, 等. 水压力作用下三峡库区侏罗系软岩裂纹扩展规律及力学机制[J]. 地质科技通报, 2023, 42(3): 1-8. doi: 10.19509/j.cnki.dzkq.2022.0036Jian W X, Pan Y L, Li L J, et al. Crack propagation law and mechanical mechanism of Jurassic soft rock in the Three Gorges Reservoir area under water pressure[J]. Bulletin of Geological Science and Technology, 2023, 42(3): 1-8(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2022.0036 [18] Li D, Yin K, Glade T, et al. Effect of over-consolidation and shear rate on the residual strength of soils of silty sand in the Three Gorges Reservoir[J]. Scientific Reports, 2017, 7(1): 1-11. [19] 刘虎虎, 缪海波, 陈志伟, 等. 三峡库区侏罗系顺层滑坡滑带土的剪切蠕变特性[J]. 岩土工程学报, 2019, 41(8): 1573-1580. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201908027.htmLiu H H, Miao H B, Chen Z W, et al. Shear creep properties of sliding-zone soil of bedding landslide in Jurassic stratum in Three Gorges Reservoir area[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(8): 1573-1580(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201908027.htm [20] 苗朝, 石胜伟, 谢忠胜, 等. 红层缓倾岩质斜坡地下水作用机制及稳定性分析[J]. 人民长江, 2016, 47(18): 50-55. https://www.cnki.com.cn/Article/CJFDTOTAL-RIVE201618011.htmMiao Z, Shi S W, Xie Z S, et al. Groundwater action mechanism and stability analysis of red-bedded gently dipping rocky slopes[J]. People's Changjiang, 2016, 47(18): 50-55(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-RIVE201618011.htm [21] 辛鹏, 吴树仁, 石菊松, 等. 黄土高原渭河宝鸡段北岸大型深层滑坡动力学机制研究[J]. 地质学报, 2014, 88(7): 1341-1352. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201407011.htmXin P, Wu S R, Shi J S, et al. Study on the dynamics of large deep-seated landslides on the north bank of Baoji section of the Weihe River on the Loess Plateau[J]. Journal of Geology, 2014, 88(7): 1341-1352(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201407011.htm [22] Hart M W. Bedding-parallel shear zones as landslide mechanisms in horizontal sedimentary rocks[J]. Environmental & Engineering Geoscience, 2000, 6(2): 95-113. [23] 张帆宇, 刘高, 谌文武, 等. 袁家湾滑坡在切坡开挖过程中的演化机理[J]. 岩土工程学报, 2009, 31(8): 1248-1254. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200908018.htmZhang F Y, Liu G, Chen W W, et al. Evolutionary mechanism of the Yuanjiawan landslide during cut slope excavation[J]. Journal of Geotechnical Engineering, 2009, 31(8): 1248-1254(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200908018.htm [24] 张恩铭, 程谦恭, 林棋文, 等. 岩体结构对岩质滑坡运动过程堆积特征的影响研究[J]. 水文地质工程地质, 2022, 49(3): 125-135. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG202203014.htmZhang E M, Cheng Q G, Lin Q W, et al. A Study of the influence of rock mass structure on the propagation processes and deposit characteristics of rockslides[J]. Hydrogeology & Engineering Geology, 2022, 49(3): 125-135(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG202203014.htm [25] 武志刚, 夏阳, 李自. 含软弱夹层的缓倾红层边坡切坡失稳特征数值模拟研究[J]. 重庆建筑, 2021, 20(11): 36-39. https://www.cnki.com.cn/Article/CJFDTOTAL-CQJZ202111011.htmWu Z G, Xia Y, Li Z. Numerical simulation of slope instability characteristics of gently dipping red-layered slopes with weak inclusions[J]. Chongqing Construction, 2021, 20(11): 36-39(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-CQJZ202111011.htm [26] 唐礼忠, 高龙华, 王春, 等. 动力扰动下含软弱夹层巷道围岩稳定性数值分析[J]. 采矿与安全工程学报, 2016, 33(1): 63-69. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201601010.htmTang L Z, Gao L H, Wang C, et al. Numerical analysis of the stability of the surrounding rock of a roadway with soft interlayer under dynamic disturbance[J]. Journal of Mining and Safety Engineering, 2016, 33(1): 63-69(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201601010.htm [27] 任杰. 含双软弱夹层顺层岩质滑坡的滑动模式及变形规律研究[D]. 太原: 太原理工大学, 2019.Ren J. Study on the sliding pattern and deformation law of rocky landslide with double soft interlayer cislayer[D]. Taiyuan: Taiyuan University of Technology, 2019(in Chinese with English abstract). [28] Kawamoto T, Ishizuka Y. An analysis of excavation in strain-softening rock mass[C]//Anon. Proceedings of the Japan Society of Civil Engineers. [S. l.]: Japan Society of Civil Engineers, 1981. [29] 亓星, 许强, 郑光, 等. 降雨诱发顺层岩质及土质滑坡动态预警力学模型[J]. 灾害学, 2015, 30(3): 38-42. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHXU201503008.htmQi X, Xu Q, Zheng G, et al. Dynamic early warning mechanics model for rainfall-induced cascading rock and soil landslides[J]. Disaster Science, 2015, 30(3): 38-42(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-ZHXU201503008.htm [30] 柴波, 陶阳阳, 杜娟, 等. 基于Hoek-Brown准则的节理岩体能量参数估算[J]. 地质科技通报, 2020, 39(1): 78-85. doi: 10.19509/j.cnki.dzkq.2020.0109Chai B, Tao Y Y, Du J, et al. Estimation of energy parameters of jointed rock masses based on the Hoek-Brown criterion[J]. Bulletin of Geological Science and Technology, 2020, 39(1): 78-85(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2020.0109 [31] 唐朝晖, 余小龙, 柴波, 等. 顺层岩质滑坡渐进破坏进入加速的能量学判据[J]. 地球科学, 2021, 46(11): 4033-4042. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX202111017.htmTang C H, Yu X L, Chai B, et al. Energetic criterion for acceleration of progressive failure of cascading rocky landslides[J]. Earth Science, 2021, 46(11): 4033-4042(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX202111017.htm [32] 程强, 周德培, 封志军. 典型红层软岩软弱夹层剪切蠕变性质研究[J]. 岩石力学与工程学报, 2009, 28(增刊1): 3176-3180. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S1090.htmCheng Q, Zhou D P, Feng Z J. Study on shear creep properties of soft interlayer in typical red-bedded soft rocks[J]. Journal of Rock Mechanics and Engineering, 2009, 28(S1): 3176-3180(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S1090.htm [33] Zhang K, Cao P, Bao R. Progressive failure analysis of slope with strain-softening behaviour based on strength reduction method[J]. Journal of Zhejiang University Science A, 2013, 14(2): 101-109. [34] 冯霄, 王禹, 刘洋, 等. 考虑软弱夹层控滑机制及其空间不确定性的顺层岩质滑坡易发性评价[J]. 地质科技通报, 2022, 41(2): 254-266. doi: 10.19509/j.cnki.dzkq.2022.0049Feng X, Wang Y, Liu Y, et al. Evaluation of landslide susceptibility of cascading rocky slopes considering the landslide control mechanism of weak inclusions and their spatial uncertainty[J]. Bulletin of Geological Science and Technology, 2022, 41(2): 254-266(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2022.0049 [35] Bizjak K F, Zupaniĉ A. Site and laboratory investigation of the Slano blato landslide[J]. Engineering Geology, 2009, 105(3/4): 171-185. [36] 简文星, 殷坤龙, 闫天俊, 等. 重庆万州区民国场滑坡基本特征及形成机制[J]. 中国地质灾害与防治学报, 2005, 16(4): 20-23. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH200504004.htmJian W X, Yin K L, Yan T J, et al. Basic characteristics and formation mechanism of landslide in Minguochang, Wanzhou District, Chongqing[J]. Chinese Journal of Geological Hazards and Prevention, 2005, 16(4): 20-23(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH200504004.htm [37] 唐雅婷, 谭杰, 李长冬, 等. 基于模型试验的动水驱动型顺层岩质滑坡启滑机制初探[J]. 地质科技通报, 2022, 41(6): 137-148. doi: 10.19509/j.cnki.dzkq.2022.0202Tang Y T, Tan J, Li C D, et al. A preliminary investigation on the initiation mechanism of kinetic water-driven cascade landslides based on model tests[J]. Bulletin of Geological Science and Technology, 2022, 41(6): 137-148(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2022.0202 [38] 邹宗兴, 唐辉明, 熊承仁, 等. 大型顺层岩质滑坡渐进破坏地质力学模型与稳定性分析[J]. 岩石力学与工程学报, 2012, 31(11): 2222-2231 https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201211009.htmZou Z X, Tang H M, Xiong C C, et al. Geomechanical modeling and stability analysis of the progressive failure of a large cascading rock slide[J]. Journal of Rock Mechanics and Engineering, 2012, 31(11): 2222-2231(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201211009.htm -
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